This invention is directed to an adapter for joining a booster to a missile. The adapter serves to self-align the booster to the missile such that the thrust vector of the booster is properly aligned in relation to the center of gravity of the missile.
Certain missile systems as, for instance, cruise missiles utilize turbojets, ramjets or other similar motors for propulsion. In order for a turbojet, a ramjet or the like to propel the missile, the missile must first be accelerated to flight speed. Normally booster rockets are utilized to accelerate surface launched missiles to flight speed. Once the fuel of the booster rocket is expended, the booster casing serves no further function. Its presence destablizes the missile, increases the weight of the missile system and increases drag. By jettisoning the booster rocket the weight of the expended booster rocket casing need not be carried by the missile, the aerodynamic drag of the booster rocket need not be experienced by the missile and the missile can have its normal stability.
To accelerate the missile to flight speed, it is important to apply the thrust of a booster rocket to the missile in such a way to assure proper pointing of the missile and transfer of maximum thrust from the booster to the missile. U.S. Pat. No. 3,855,789 describes a motor that serves both as a rocket motor and a ramjet motor. In this patent expendable baffles throttle the throat of a ramjet motor down to a smaller size allowing the throttled ramjet motor to be used as a rocket motor. Upon the expenditure of the rocket motor fuel supply carried within the ramjet motor casing, the throttling baffles are jettisoned and the motor is then operated in a ramjet mode. While this arrangement certainly is utilitarian, the fuel charge for the rocket motor, since it must be carried within the ramjet motor housing, is restricted to only the volume of the ramjet motor housing.
In order to provide for an independent booster rocket, an attachment mechanism must be utilized between the booster rocket and the missile that allows for correct alignment of the thrust vector of the booster rocket with the missile. Theoretically this can be achieved in one of two ways. The first way is to provide for an adjustable adapter that allows for adjustments of the booster to align it with the missile. Concurrently with this, necessary measuring devices or dedicated tooling must be provided for assessing when the correct alignment is achieved. A second method and easier method would be to provide an adapter that is self-adjusting or is inherently self-aligning. Such an adapter would inherently be more desirable than an adjustable adapter since it avoids the necessity of fabricating special tooling and aligning equipment and avoids any labor necessary in achieving alignment of the booster rocket with the missile.
Once the fuel supply of an external booster rocket has been spent, in order to have the correct missile stability, reduce the weight of the missile and eliminate any drag caused by the booster rocket it is desirable to jettison the booster rocket. The more complicated the structure that is utilized to attach the booster rocket to the missile the more complicated ejection or jettison of the booster rocket can become. Further, in ejecting a spent booster rocket it is also desirable not to impart any momentum to the missile that would tend to deviate the missile from its line of flight.
In order to achieve better ballistic flight characteristics U.S. Pat. No. 4,348,957 describes a method of jettisoning the nozzle exit cone of a rocket motor after burnout. In this patent a linear shaped charge positioned around the throat of a rocket nozzle is exploded to sever the rocket nozzle about its throat. This results in a boat tail configuration at the aft end of the missile after jettisoning of the rocket nozzle exit cone. As utilized in U.S. Pat. No. 4,348,957 the linear shaped explosive charge is used to redefine the shape of the aft end of a missile after booster burnout.